Controlled noise-reduction means for typewriters



y 19, 1953 c. SCHRODER 39,020

CONTROLLED NOISE-REDUCTION MEANS FOR TYPEWRITERS Filed Dec. '25, 1949 2 Sheets-Sheet l & INVENTOR.

CHARLES SCHRODER ATTORNEY May 19, 1953 c. SCHRODER CONTROLLED NOISE-REDUCTION MEANS FOR TYPEWRITERS 2 Sheets-Sheet 2 Filed Dec.

INVENTOR.

2'; -j CHARLES SCHRODER BY $4M] ATTORNEY l atenteol May 1%, l53

amen

@FFiCE Charles Schroder, West Hartford, Conn, assignor to Underwood Corporation, New York, N. .Y., 2i corporation of Delaware Application December 23, 1949, Serial No. 134,703

11 Claims. 1%,

This invention relates to controlled noise-reductlon means for typewriters and more particularly to noise-reduction means in association with mechanical-vibration and safety controls.

Objectionable noise in typewriter operation stems in most instances from the following causes: type-bar impact against the paper on the platen, carriage arrest in tabulation and return, case-shitting of the type-basket, the escapement mechanism in its letter iced opera- 'tions, and the bottoming of the space-bar against a limiting stop. In power-driven typewriters some of these noises :may he accentuated and the electric motor may itself set up sound vibrations eapable'of transmission to the desk or platform on which the machine is mounted and to other 13311161501 parts .of the machine Where th noise may he intensified.

Elf-arts have been made .over a long period to tiatecl by these mechanisms in their normal operation and to avoid intensification of the sound by inrberiering with or deadening the sound vi ovations before they reach parts oi the machine or the machine mounting which nave special sound-transmitting characteristics. Many difficulties have been encountered in the attempts to improve typewriters in these respects. Many rubber-=foot ideas and mountings of various mechanisms on springs or in rubber orfelt .or-the like have been tried and discarded, principally nwlnotn their failure tn obtain thp desired nm'se cause of the continuous prec1sion required during the life of the machine and the failure of the devices, in the manner they have been used, previously, to maintain a uniform condition, owing to oxidation, wear, matting and other reasons.

The present invention has as one of its objects to provide a novel assembly of a typewriter base, mask, and a frame carrying the working parts, which results in va great amount of damping of sound vibrations and controls .the mechanical vibrations of the working parts of the :rnac'hine to the endthat the working parts function continuously as intended and as necessary to proper typewriter operation and. results.

Another object of the invention :is :to provide, in association with such devices or damping or deadening the sound wibrations, certain safety means iior preventing the straining or breakin of parts which might otherwise be so affected by use following the introduction of the noise-reouclllg lllualls.

silient material for holding the base generally spaced from a, platform, a mask supported from said base comprising upstanding closure panels, a skeleton frame within said mask having mounted thereon the following: a platen carriage, a set of type-bars, means for driving said type-bars, for case-shifting and for moving said platen carriage, comprising an electric motorand transmission devices; means mounting the frame on the base comprising a plurality of sounddeadening diaphragms which hold the skeleton frame, and the parts mounted thereon, otherwise normally spaced from the base and the mask and allow for typing and platen-carriage movements effected by the motor, and cushion-stopmeans in part on said base and in part on said frame for determining the maximum amplitude of vibratory movement of the frame, relative to the base, permitted by said diaphragms.

10. A machine of the class described comprising a base having supporting members of resilient material for holding the base generally spaced from a platform, a mask supported from said base comprising upstanding closure panels, a skeleton frame within said mask, having mounted thereon the following: a, platen carriage, a set of type bars, means for driving said type-bars, for case-shifting and for moving said platen carriage, comprising an electric motor and transmission devices; means mounting the frame on the base comprising a plurality of sound-deadening diaphragms which hold the skeleton frame, and the parts mounted thereon, otherwise normally spaced from the base and the mask and allow for typing and platen-carriage movements effected by the motor, cushionstop-means in part on said base and in part on said frame for determining the maximum amplitude of vibratory movement of the frame relative to the base permitted by said diaphragms, and certain of said diaphragms being located in a line substantially between the said motor and certain of said resilient base-supporting members.

11. A typewriter comprising a substantially horizontal base, a mask supported solely from said base and including upstanding closure panels, a skeleton frame within said mask and supporting an escapement-controlled paper carriage and type bars and other operating parts of the typewriter, said frame presenting horizontally a generally rectangular outline, a plurality of rubber-in-shear diaphragms mounting the frame on the base, there being one said diaphragm adjacent each of the four corners of the rectangular frame outline, said diaphragms holding the frame normally generally spaced from the base and from the mask, with a capability of vertical vibratory and tilting movements of the frame relatively to the, base, and'a vibrationcontrol device arranged intermediate the two diaphragms at each side of the frame and includingan adjustable stop means in part on the frame and in part on the base for variably determining the maximum, amplitude of vertical vibrations and tilting movements of the frame.

CHARLES SCHRODER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,578,399 Corcoran Mar. 30, 1926 1,656,268 Daniel Jan. 17, 1928 1,981,034 Gabrielson Nov. 20, 1934 2,160,297 Thompson May 30, 1939 2,351,725 Wack June 20, 1944 2,366,107 Helmond Dec. 26, 1944 2,489,696 Boyden Nov. 29, 1949 FOREIGN PATENTS Number Country Date 412,557 Great Britain June 25, 1934 l l l l l 

